Securities - Securities pledged (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Securities
Securities pledged	$ 636		$ 636		$ 719
Securities of any one issuer, other than U.S. Government, greater than 10% of shareholders equity	0		$ 0		$ 0
Shareholders equity representing a concentration risk for any one securities investment (as a percent)			10.00%		10.00%
Sales of securities	$ 0	$ 0	$ 0	$ 0